Yin Yang with Background

This program is similar to the last one, but adds an animated color background.

The background is made using 3 large sprites (tiles), which are tinted with RGB values
which are 120 degrees apart from each other on the hue wheel. Each sprite uses a radial
gradient which goes from full opacity to transparency, making it look like a large fuzzy dot.

The tints are animated to create constant color movement in the background.